CVE-2023-43826: Apache Guacamole

High severity, CVSS 8.8. EPSS: 0.9% chance of exploitation in the next 30 days.

Apache Guacamole 1.5.3 and older do not consistently ensure that values received from a VNC server will not result in integer overflow. If a user connects to a malicious or compromised VNC server, specially-crafted data could result in memory corruption, possibly allowing arbitrary code to be executed with the privileges of the running guacd process. Users are recommended to upgrade to version 1.5.4, which fixes this issue.

Affected products

• Apache Guacamole: up to and including 1.5.3

Published 2023-12-19. Last modified 2026-06-17.